Sewing machine



Oct. 23, 1934.

K. PFAFF SEWING MACHINE Filed March 2, 1932 2 Sheets-Sheet l INVENTOR' A TTORNEYS.

)Ct. 23, 1934. PFAFF 1,978,281

SEWING MACHINE Filed March 2, 1952 2 Sheets-Sheet 2 INVENTOR.

fi. P1215 BYIM A TTORNEYS.

Patented Oct. 23, 1934 UNITED STATES PATENT OFFICE Application March 2, 1932, Serial No. 596,331

In Germany October 26, 1928 5 Claims.

This application is a continuation in part of my (Jo-pending application filed June 11, 1929, Serial No. 369,978.

The invention relates to the construction of 5 the upper parts of sewing machines of all types.

Its object is to so form the body which carries the gear mechanism, that is, the arm and base plate, that they can not only be cast in the simplest manner, that is to say, without cores, but

above all that they present a considerable reduction in weight as compared with previous models,

with the further advantage of facilitating the fitting of the driving mechanism and rendering the mechanism accessible and visible from all sides.

With this object in view, according to the invention the upper frame member comprises the standard and the arm extended therefrom are in the form of a skeleton structure, the arm which has the bearings at its opposite ends for the main shaft, being apertured between said bearings, thereby allowing access to the main shaft and the operating members associated therewith from both sides of the machine. The arm comprises upper and lower flange members with a central rib on the inner side of each member, the ribs of the two flange members being spaced from one another so as to form an equivalent of an I beam from which the major part of the rib has been removed. The base is constructed in the form of a grid comprising a plurality of longitudinal and transverse walls connected together.

In order to spare any supplementary work on the carrier construction and to protect the gear from dust and to give a handsome appearance to the machine, the cast skeleton is covered with a lacquered metal cover plate.

An example of an upper part of a sewing machine constructed according to the invention is shown in the accompanying drawings. In the 40 drawings:

Figure 1 shows the upper part of the machine with the mechanism in elevation and the casing in section;

Figure 2 is a cross section;

Figure 3 is a horizontal section through the axis of the main spindle;

Figure 4 shows the base plate from underneath; and

Figure 5 is a perspective view of the upper frame member and base.

Referring to the drawings, the upper frame comprises the standard 9 and the arm I extending in a horizontal direction therefrom and having two bearings 2 and 3 at its opposite ends for supporting the main shaft. The arm 1 intermediate the bearings 2, 3 comprises upper and lower flange members 21, 22 which are provided with inner ribs 23, 24, respectively, the two ribs being spaced from one another so that the arm forms the equivalent of an I beam from which the major part of the web has been removed. By this construction the arm 1 is apertured intermediate the bearings so as to form an open skeleton structure allowing access to the main shaft and the operating members associated therewith from 5 both sides of the machine which considerably fa.- cilitates the accurate fitting of the working parts housed in the arm. The arm supports at its front end a needle head 11, and the standard and arms thus carry the operating parts of the machine.

The standard 9 is attached to the base 4 by means of screw 91 which are screwed into tapped holes formed in the underside of the bottom of the standard. The base 4 is formed from a plurality of longitudinal walls 41 and transverse walls 6 which are connected together in such a manner as to form a grid structure. Owing to the open formation of the base, the fitting of the working parts thereon is much simplified as com- 30 pared with previous arrangements, owing to the free access from above and below.

The upper frame member comprising the standard 9 and the arm 1 is covered by separable plates 7 and '71 respectively, one on each side of 5 the machine, each plate extending around and beneath the arm so as to cover entirely one side of the frame, while the base is covered by a plate 8 forming the work plate. The attachment of the plates to the base and the upper frame member is preferably'effected by means of screws, so that the cover can be removed from the machine. Obviously, openings are provided in the cover through which some of the parts may extend, such as the needle carrying bar and the driving wheel, the latter being located behind the bearing 3 on a shaft which extends through the opening 12.

The present novel construction of the upper part of the sewing machine assists considerably in simplifying the production of the machines and in cheapening them, and in repairs a much easier interchange of parts is made possible.

In order to attain the utmost possible reduction in weight the upper part, instead of being 05 made of cast iron, may consist of a lighter metal such as aluminum, chilled castings or stamped metal. This is especially important with folding or portable sewing machines. Upper parts made of chilled castings and stamped metal have the additional advantage that supplementary finishing work on them is almost entirely obvlated.

What I claim is:

1. A sewing machine frame comprising a base, and an upper frame member mounted on said base including a horizontally extending arm having a substantially vertical web element extending longitudinally thereof and bearings adjacent its ends having their axes aligned, a line through the said axes lying within the plane of the web element, the portion of the web between said bearings being cut away so as to form a space accessible from both sides of the frame through which an operating shaft mounted in said bearings may extend.

2. A sewing machine frame comprising a base, and an upper frame member mounted on said base including a horizontally extending arm formed of an I-beam having a vertical web, said arm having bearings adjacent its ends to receive an operating shaft, the axes of said bearings being aligned, the line of the axes lying within said web, said web having its central portion cut away between said bearings so as to form a space accessible from both sides of the arm through which an operating shaft mounted in said bearings may extend.

3. A sewing machine frame comprising a base, an upper skeleton frame member mounted on said base including a horizontally extending arm and a needle head supported by said arm, said member having means to support the operating parts of a sewing machine, and a removable cover formed of a plurality of separable parts surrounding and concealing said frame member, said cover extending beneath said arm and having openings therein through which operating parts of the machine can extend.

4. In a sewing machine frame as claimed in claim 3, said base comprising a grid structure, and a plate covering said base.

5. In a sewing machine frame as claimed in claim 3, said arm comprising an I-beam having its central portion cut away so as to form a space accessible from both sides of the arm through which an operating member may extend.

KARL PFAFF. 

